Dicyclohexylcarbodiimide → HCID 57093356, compound

Participants

Reaction Steps

A 1.04 g portion of (2S,4S)-4-benzoylthio-1-(p-nitrobenzyloxycarbonyl)proline was dissolved in 20 ml of tetrahydrofuran, and, with cooling on an ice bath, 0.55 g of N-hydroxybenzotriazole and 1.49 g of dicyclohexylcarbodiimide were added to the solution, followed by 1 hour of reaction with stirring at room temperature. To the solution were added 0.88 g of 1-((2S)-4-(p-nitrobenzyloxycarbonyl)amino-2-hydroxybutyryl)piperazine and 0.49 g of triethylamine, followed by 1 hour of reaction at room temperature. After concentration of the solvent, the residue was mixed with ethyl acetate to remove insoluble material, washed with sodium bicarbonate aqueous solution, citric acid aqueous solution and sodium chloride aqueous solution in that order and then dried over sodium sulfate, followed by evaporation of the solvent under a reduced pressure. Thereafter, the resulting residue was subjected to a silica gel column chromatography to yield 1.80 g of (2S,4S)-4-benzoylthio-1-(p-nitrobenzyloxycarbonyl) -2-((1-((2S)-4-(p-nitrobenzyloxycarbonyl) amino-2-hydroxybutyryl)piperazine-4-yl)carbonyl)pyrrolidine.

Provenance & Evidence